kernel/fork.c:1962: warning: bad line:

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4853c74bd7ab7fdb83f319bd9ace8a08c031e9b6
commit: 6ae930d9dbf2d093157be33428538c91966d8a9f pid: add pidfd_prepare()
date:   5 months ago
config: nios2-defconfig (https://download.01.org/0day-ci/archive/20230817/202308172133.Hs40Ti6o-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230817/202308172133.Hs40Ti6o-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308172133.Hs40Ti6o-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/fork.c:1261: warning: Function parameter or member 'mm' not described in 'set_mm_exe_file'
   kernel/fork.c:1261: warning: Function parameter or member 'new_exe_file' not described in 'set_mm_exe_file'
   kernel/fork.c:1298: warning: Function parameter or member 'mm' not described in 'replace_mm_exe_file'
   kernel/fork.c:1298: warning: Function parameter or member 'new_exe_file' not described in 'replace_mm_exe_file'
   kernel/fork.c:1350: warning: Function parameter or member 'mm' not described in 'get_mm_exe_file'
   kernel/fork.c:1369: warning: Function parameter or member 'task' not described in 'get_task_exe_file'
   kernel/fork.c:1393: warning: Function parameter or member 'task' not described in 'get_task_mm'
>> kernel/fork.c:1962: warning: bad line: 
>> kernel/fork.c:1983: warning: Function parameter or member 'ret' not described in '__pidfd_prepare'
>> kernel/fork.c:1983: warning: Excess function parameter 'pidfd' description in '__pidfd_prepare'
>> kernel/fork.c:2032: warning: Function parameter or member 'ret' not described in 'pidfd_prepare'
>> kernel/fork.c:2032: warning: Excess function parameter 'pidfd' description in 'pidfd_prepare'
   kernel/fork.c:3048: warning: expecting prototype for clone3(). Prototype was for sys_clone3() instead


vim +1962 kernel/fork.c

  1953	
  1954	/**
  1955	 * __pidfd_prepare - allocate a new pidfd_file and reserve a pidfd
  1956	 * @pid:   the struct pid for which to create a pidfd
  1957	 * @flags: flags of the new @pidfd
  1958	 * @pidfd: the pidfd to return
  1959	 *
  1960	 * Allocate a new file that stashes @pid and reserve a new pidfd number in the
  1961	 * caller's file descriptor table. The pidfd is reserved but not installed yet.
> 1962	
  1963	 * The helper doesn't perform checks on @pid which makes it useful for pidfds
  1964	 * created via CLONE_PIDFD where @pid has no task attached when the pidfd and
  1965	 * pidfd file are prepared.
  1966	 *
  1967	 * If this function returns successfully the caller is responsible to either
  1968	 * call fd_install() passing the returned pidfd and pidfd file as arguments in
  1969	 * order to install the pidfd into its file descriptor table or they must use
  1970	 * put_unused_fd() and fput() on the returned pidfd and pidfd file
  1971	 * respectively.
  1972	 *
  1973	 * This function is useful when a pidfd must already be reserved but there
  1974	 * might still be points of failure afterwards and the caller wants to ensure
  1975	 * that no pidfd is leaked into its file descriptor table.
  1976	 *
  1977	 * Return: On success, a reserved pidfd is returned from the function and a new
  1978	 *         pidfd file is returned in the last argument to the function. On
  1979	 *         error, a negative error code is returned from the function and the
  1980	 *         last argument remains unchanged.
  1981	 */
  1982	static int __pidfd_prepare(struct pid *pid, unsigned int flags, struct file **ret)
> 1983	{
  1984		int pidfd;
  1985		struct file *pidfd_file;
  1986	
  1987		if (flags & ~(O_NONBLOCK | O_RDWR | O_CLOEXEC))
  1988			return -EINVAL;
  1989	
  1990		pidfd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
  1991		if (pidfd < 0)
  1992			return pidfd;
  1993	
  1994		pidfd_file = anon_inode_getfile("[pidfd]", &pidfd_fops, pid,
  1995						flags | O_RDWR | O_CLOEXEC);
  1996		if (IS_ERR(pidfd_file)) {
  1997			put_unused_fd(pidfd);
  1998			return PTR_ERR(pidfd_file);
  1999		}
  2000		get_pid(pid); /* held by pidfd_file now */
  2001		*ret = pidfd_file;
  2002		return pidfd;
  2003	}
  2004	
  2005	/**
  2006	 * pidfd_prepare - allocate a new pidfd_file and reserve a pidfd
  2007	 * @pid:   the struct pid for which to create a pidfd
  2008	 * @flags: flags of the new @pidfd
  2009	 * @pidfd: the pidfd to return
  2010	 *
  2011	 * Allocate a new file that stashes @pid and reserve a new pidfd number in the
  2012	 * caller's file descriptor table. The pidfd is reserved but not installed yet.
  2013	 *
  2014	 * The helper verifies that @pid is used as a thread group leader.
  2015	 *
  2016	 * If this function returns successfully the caller is responsible to either
  2017	 * call fd_install() passing the returned pidfd and pidfd file as arguments in
  2018	 * order to install the pidfd into its file descriptor table or they must use
  2019	 * put_unused_fd() and fput() on the returned pidfd and pidfd file
  2020	 * respectively.
  2021	 *
  2022	 * This function is useful when a pidfd must already be reserved but there
  2023	 * might still be points of failure afterwards and the caller wants to ensure
  2024	 * that no pidfd is leaked into its file descriptor table.
  2025	 *
  2026	 * Return: On success, a reserved pidfd is returned from the function and a new
  2027	 *         pidfd file is returned in the last argument to the function. On
  2028	 *         error, a negative error code is returned from the function and the
  2029	 *         last argument remains unchanged.
  2030	 */
  2031	int pidfd_prepare(struct pid *pid, unsigned int flags, struct file **ret)
> 2032	{
  2033		if (!pid || !pid_has_task(pid, PIDTYPE_TGID))
  2034			return -EINVAL;
  2035	
  2036		return __pidfd_prepare(pid, flags, ret);
  2037	}
  2038	

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